JMS Properties for Messages

[Micha228]

Hi @matrober-uk

Im migrating right now a java application to a golang microservice architectur but im struggeling a little bit with extracting
JMS Propertys of Messages. We had talked a few weeks ago in a call about the QueueBrowser wich is working fine for me.
But im not able to extract following Propertys of the messages.

• JMS_IBM_MQMD_Format
• JMS_IBM_MQMD_CodedCharSetId
• JMS_IBM_MQMD_MsgType
• JMS_IBM_MQMD_MsgId
• JMS_IBM_Format
• JMS_IBM_Encoding
• JMS_IBM_Character_Set
• JMS_Priority
• JMS_IBM_PutApplType
• JMSXAppID
• JMS_IBM_MQMD_ApplOriginData
• JMSGroupID
• JMSExpiration
• JMS_IBM_PutTime
• JMS_IBM_PutDate

I think in the java library was this archived by setting the Property WMQ_MESSAGE_BODY to WMQ_MESSAGE_BODY_MQ
for the destination.
But in the golang pack i didnt find any options like this.
Is there a possibility to extract these information of JMS messages ?

Best regards

Michael

[matrober-uk]

Hi @Micha228 - thanks for your questions above. I will check through the list of properties over the next few days to see how straightforward it is to add those in and post a comment back here to confirm.

[Micha228]

Hey @matrober-uk,
thanks a lot for checking. Im looking forward to hear from you.

[matrober-uk]

Hi @Micha228

I've done a first pass look at the message properties and I have a few questions as follows please:

1. Where relevant do you need to be able to set all these properties when sending in Golang JMS (e.g. ApplOriginData, CCSID, ApplType, Priority, GroupID/Seq), or is it just about reading those properties for a message that is sent using a different type of client such as Java JMS?
2. Are you happy to use the "JMS_IBM_" field names to retrieve items such as Format, CCSID, MsgType instead of the "JMS_IBM_MQMD_" style naming, or do you specifically need both?
3. Similarly for JMS_IBM_MQMD_MsgId, is it ok for you to call GetJMSMessageID() instead to retrieve that value?

Implementation notes (for my reference)

#1 https://www.ibm.com/docs/en/ibm-mq/9.2?topic=mjmomm-mapping-mq-fields-onto-jms-fields-incoming-messages
#2 https://www.ibm.com/docs/en/ibm-mq/9.2?topic=mjmomm-mapping-jms-fields-onto-mq-fields-outgoing-messages
#3 https://www.ibm.com/docs/en/ibm-mq/9.2?topic=application-jms-message-object-properties


JMS field name                     MQMD field             Equivalent?             Notes
---------------------------------------------------------------------------------------------------
JMS_IBM_MQMD_Format                Format                 JMS_IBM_Format
JMS_IBM_MQMD_CodedCharSetId        CodedCharSetId (int)   JMS_IBM_Character_Set            
JMS_IBM_MQMD_MsgType               MsgType (integer)      JMS_IBM_MsgType
JMS_IBM_MQMD_MsgId                 MsgId  (byte[])        JMSMessageID (similar)

JMS_IBM_MQMD_ApplOriginData        ApplOriginData (string)

JMS_IBM_Format                     Format (string)
JMS_IBM_Encoding                   Encoding (int)                                 BytesMessage only (see #2)
JMS_IBM_Character_Set              CodedCharacterSetId (int)                      BytesMessage only (see #2)
JMS_IBM_PutTime                    PutDate (string)
JMS_IBM_PutDate                    PutTime (string)
JMS_IBM_PutApplType                PutApplType (int)

JMS_Priority                       Priority               JMSPriority
JMSExpiration                      JMS_IBM_MQMD_Expiry (related)                  10ths second (e.g. 1 min = 600) so add to PutTimestamp

JMSXGroupID                        GroupId
(JMSXGroupSeq added)               MsgSeqNumber 
JMSXAppID                          PutApplName (string)                           Test to update at: https://github.com/ibm-messaging/mq-golang-jms20/blob/main/applname_test.go#L66

[Micha228]

Hey @matrober-uk,

1. In the main thing we need to read this fields for messages wich send by other application.
   We need to have the possibility to set only a few of them activly by our application.
   These would be :

• JMS_IBM_MQMD_CodedCharSetId
• JMS_IBM_MQMD_Format
• JMS_IBM_MQMD_MsgType

2. I think we will need both JMS_IBM_MQMD and JMS_IBM.
   In the old application for example when we create a message we set the field IBM_JMS_FORMAT. But when we are browsing a queue we will read out IBM_JMS_MQMD_FORMAT. Im not really sure what the difference is. Are the MQMD Fields used internal and the other via JMS Clients ?

3. For the IBM_JMS_MQMD_MsgId i think it is ok to go with calling GetJMSMessageId()

[matrober-uk]

Hi @Micha228 - I've attached a branch (https://github.com/ibm-messaging/mq-golang-jms20/tree/header-properties) to this issue that implements the behaviour for 8 of the 16 properties as described here and as below.

Field name                    Example                                                Notes
---------------------------------------------------------------------------------------------------------------------------------------------------------
JMS_IBM_PutDate               msg.GetStringProperty("JMS_IBM_PutDate")               YYYYMMDD
JMS_IBM_PutTime               msg.GetStringProperty("JMS_IBM_PutTime")               HHMMSSTH
JMS_IBM_Format                msg.GetStringProperty("JMS_IBM_Format")                MQSTR
                              msg.SetStringProperty("JMS_IBM_Format", "MYFMT")
JMS_IBM_MQMD_Format           msg.GetStringProperty("JMS_IBM_MQMD_Format")           MQSTR
                              msg.SetStringProperty("JMS_IBM_MQMD_Format", "MYFMT")
JMS_IBM_MQMD_MsgId            msg.GetJMSMessageID()
JMS_IBM_MQMD_ApplOriginData   msg.GetStringProperty("JMS_IBM_MQMD_ApplOriginData")
JMSExpiration                 msg.GetJMSExpiration()
JMSXAppID                     msg.GetStringProperty("JMSXAppID")                     JMSXAppID / PutApplName is set using ConnectionFactory.ApplName

You're welcome to download that branch to try out the behaviour if it's useful, before I get to look at the remaining properties.

[Micha228]

Hey @matrober-uk,

thanks for your implementation. I have downloaded your branch and give it a test.
Using the fields was working fine for me.
It would be great if you can add the other fields also. Looking forward to hear from you.

Best regards
Michael

[matrober-uk]

Hi @Micha228 - I've merged the full set of changes we discussed into the "main" branch (under PR #52).

Details of the Get/Set options now supported are included in the README in the section on Special header properties supported.

Please can you add a comment to this issue when you've had an opportunity to try out the new features?

[matrober-uk]

Closing as implemented, included in tag v1.8.0.

Please feel free to comment/reopen if necessary.

[Micha228]

Hey @matrober-uk

thank you very much for implementing.
I will test it and leave a comment. 👍

[Micha228]

Hey @matrober-uk

i have tested your changes and its working fine for me.
Nice job

[matrober-uk]

great, thanks for confirming @Micha228 - I'm pleased the new options are working as expected for you! 👍